1. Field of the Invention
The present invention relates to a primer composition capable of providing a satisfactory adhesion property to a nonadhesible or hard-to-bond material such as polyolefin and high solid paint (i.e., highly corrosion-resistant paint).
2. Description of the Related Art
Recently, parts such as automobile parts heretobefore manufactured from steel materials are being substituted with resin products for the purpose of reducing the weight and cost thereof. Moreover, there has been increasing the proportion of a highly corrosion-resistant paint, namely, a so-called high solid paint, as paints for automobiles, etc.
Those materials having excellent corrosion-resistant properties, such as resins (e.g., polyolefin) and high solid paints, generally have poor adhesion properties, and it is difficult to obtain the good adhesibility (or adhesion properties) when conventional primers are used.
For this reason, attempts have been made to obtain good adhesibility when these hard-to-bond materials are bonded, by adding various additives to the primers. For example, Japanese Unexamined Patent Publication (Kokai) No. 61-152755 proposes a primer composition containing, for example, chlorinated polyolefin.
However, these proposed primer compositions are still not sufficient to provide the desired good adhesive properties to the hard-to-bond materials, and therefore, there is a need for such a primer composition that can bond hard-to-bond materials with good adhesivity.